My in ground plaster pool was completed in July 0f 2008, we enjoyed it for two months and closed it. We opened last year in May and enjoyed it until October of 2009. I opened it two weeks ago and there are all these little bumps all over the plaster and they are rough to the touch. The pool uses the salt chlorine system and we have chosen not to use any other chemicals in the pool, opening early and closing late to avoid algae issues (which we have never had any of). Does anyone have any idea what these bumps are and how I might remove them? I tried brushing and it is not removing them but maybe I just need more elbow grease? My nice smooth plaster is no longer and I am feeling bummed.